Improvement in mouth-pieces for speaking-tubes



T. c.slM|TH. MouthPieces for Speaking-Tubes. No.153,856." PafenzedAug.4,1a74.

THE GRAPHIC CO-PHOYO-LITHJHI14I PARK PlACEJX.

UNITED STATES PATENT FFICE.

THOMAS C. SMITH, OF BROOKLYN, NEW YORK.

IMPROVEMENT IN MOUTH-PIECES FOR SPEAKING-TUBES.

Specification forming part of Letters Patent N0. 153,856., dated August 4, l874: application filed June 5, 1874.

To all whom it may concern:

Be it known that I, THOMAS G. SMITH, of Brooklyn, in the county of Kings and. State of New York, have invented certain new and useful Improvements in Mouth Pieces for SpeakingTnbes, of which the following is a specification My improvement chiefly relates to simplicity and cheapness of construction, while it is neater or cleaner in use and of more ornamental appearance than those previously used.

Figure 1 represents a longitudinal section through the center of the apparatus. a a represent the porcelain mouth-piece with stem attachment b, the mouth-piece and stem being formed together of the same material and constituting one piece. d represents the whistle, attached by a hinge, f, which serves, first, as a signal to call attention to the tube, and, secondly, to nearly close the mouth-piece, so that an escape of air through a small aperture, g, will lift a valve, and thereby indicate among several pipes that which has been called from. h is a lever, by means of which the whistle is turned on its hinge upward, opening the aperture of the mouth-piece to receive the voice.

Fig. 2 is a cross-section of the mouth-piece on the line oo .r of Fig. l. The arm of the leverh is so adjusted that it closes the small aperture g in the act of lifting the whistle d for admitting the voice of the speaker.

At either end of the speaking-tube, in practice, the signal or call is made by blowing into the tube; at the opposite end the whistle is then sounded; the valve over the small vent is at the same time lifted and thrown backward, indicating the tube through which the call has been made. The person replying presses the lever h backward, and thus lifts March, 1874.

THOMAS O. SMITH.

Witnesses:

D. D. PARMELEE, TIMOTHY PERRY. 

